As an outdoor product, tents become a necessity of people who like outdoor recreation activities such as travelling, camping and nature experience at present, and currently, the tents used for outdoor recreation have many types, including a large-size type and a small-size type, and also including a square type, a circular type and a hexagonal type. A tent mainly consists of tent cloth and a tent frame for supporting the tent cloth, a common tent support is generally formed by connecting a plurality of groups of support rods with a top rod, and the top rod forms top support. A well-known tent has the general defect that the structure is relatively complicated, for some tents, a pivoting base is arranged at the top to connect a plurality of tent top rods, so as to unfold and support the tent and increase a use area thereof, however, in this case, rod pieces of the tent are increased, a weight is larger, it is difficult and time-wasting to support and build the tent, and a manufacturing cost is also increased. For a top flat tent only adopting a transverse rod as the top rod, the top rod only achieves the supporting action on the top surface, a supporting area is only in one direction, a supporting surface cannot be formed by unfolding, a top area of the unfolded tent is limited and a use space of the tent cannot be further increased.